EAGER Collaborative Research: Development of Synthetic Fly Ash Glass as a Model System for Investigating Fly Ash Reactivity

“这项奖励是根据2009年美国复苏和再投资法案（公法111-5）资助的。”本EAGER研究的目的是证明使用合成粉煤灰玻璃作为系统研究粉煤灰反应性的模型的可行性，而不是使用真实的粉煤灰。它将证明合成粉煤灰样品将产生与实际粉煤灰一致的反应性数据，同时使后者无法使用的分析方法得以使用。这将为今后对粉煤灰反应性的系统研究奠定基础。在本研究中，我们将根据在真实粉煤灰中发现的特征团簇的成分来制备几种粉煤灰玻璃。粉状玻璃样品将与整个粉煤灰样品并行水化并进行分析。此外，典型尺寸为1厘米的合成玻璃巨石将在单独的特氟龙容器中水化。这种方法可以通过玻璃浸出率的质量平衡作为溶液化学和玻璃成分的函数进行定量测定。它还允许使用扫描电镜和微拉曼分析凝胶层的后续详细分析。这对于整个飞灰来说是不可行的。这项研究将有助于通过提高对控制反应性的基本因素的理解，加速混凝土工业对粉煤灰的利用。这将导致根据其反应性更好地预测粉煤灰玻璃在水泥浆体中的行为，而不是通过常规测试进行反复试验。这反过来将导致更有效地利用粉煤灰，这将提高利用率，提供废物的经济利用和更低的二氧化碳排放。

"This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5)."The objective of this EAGER research is to demonstrate the feasibility of using synthetic fly ash glass as a model for systematic studies of fly ash reactivity instead of using real fly ash. It will demonstrate that synthetic fly ash specimens will produce reactivity data consistent with that of actual fly ashes, while at the same time enabling the use of analytical methods that cannot be used on the latter. This will establish the basis for future systematic studies of fly ash reactivity. In this proposed research, several fly ash glasses will be prepared with compositions based on those of characteristic clusters identified in real fly ash. Powdered glass samples will be hydrated in parallel with whole fly ash specimens and analyzed. In addition synthetic glass monoliths with typical dimensions of 1 cm will be hydrated in individual Teflon containers. This approach enables quantitative determination by mass balances of the glass leach rates as a function of solution chemistry and glass composition. It also permits the subsequent detailed analysis of the gel layer using SEM and micro-Raman analysis. This is not feasible for whole fly ashes.This research effort will help accelerate the usage of fly ash by the concrete industry through an improved understanding of fundamental factors controlling reactivity. This will lead to the better prediction of fly ash glass behavior in cement paste based on its reactivity instead of trial and error by conventional tests. This in turn will lead to a more effective use of fly ash, which will increase the utilization rate and provide economical use of a waste material and lower emissions of CO2.